Dry-pipe fire-extinguishing apparatus.



J. H. DERBY.

Patented Aug. 28, I900.

DRY PIPE FIRE EXTINGUISHING APPARATUS.

(No Model.)

[Application filed Dec. 22, 1899.)

WITNESSES.

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DRY -PIPE FlRE-EXTINGUISHING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 656,837, dated August 28, 1900.

Application filed December 22, 1899- Serlal No. 741,271- (No model.)

To all whom it may concern:

Be it known that 1, JOHN H. DERBY, a citi- 'zen of the United States, residing at Brookline, in the county of Norfolk and State of Massachusetts, have invented certain new and useful Improvements in Dry-Pipe Fire- Extinguishing Apparatus, of which the following is a specification.

My invention is intended to be used in connection with dry-pipe sprinkling systems forautomatically extinguishing fires and to have in such connection the same functions as a dry-pipe valve, serving to exclude water from the system of sprinkling-pipes except in case of fire.

It has been found in practice that devices of the class above referred to are liable to be more or less defective in certain particulars, being subject to corrosion of the moving parts or to the sticking of the valve and a consequent failure to open, due to corrosion and other causes, or to a lack of sensitiveness, or to leakage, or having complicated mechanism, or having a tendency to water column, or to be operated by a water-hammer, or be- :ing subject to other objections of less impor' tance, or to combinations of the above objections, all of which my present invention is intended to overcome.

To this end I provide a frangible device by means of which the water is normally kept out of the sprinkling-pipe system, and I combine therewith means whereby said frangible device will be automatically broken upon the occurrence of a fire, thereby directly or indirectly permitting the water to enter said systern and to be thrown therefrom upon the fire.

An apparatus embodying a preferred form of my invention is illustrated in the accompanying drawings, in which Figure 1 is a central vertical section of said apparatus, with its immediate pipe connections. Figs. 2 and 8 are transverse sections taken, respectively, on the lines a; as and y y in Fig. 1 looking downward.

In the drawings, 2 represents a vertical pipe, which may be composed of any convenient number of sections suitably secured to gether to provide a watertight tube having a height suitable for the purpose, hereinafter explained. At or near its bottom the pipe 2 is provided with an opening 3, at which point it is bolted to the inlet or supply pipe 4:, and above the opening 3 is fixed a plate 5, which normally closes completely said pipe 2 and is made of frangible material, preferably glass,

of sufficient thickness to resist the water-' pressure below it. This plate 5 may conveniently be contained within an enlarged chamber 6 and secured firmly and tightly to its seat 7 by a ring-shaped Wedge 8, fitted between said plate and the opposite wall of the chamber 6 and adapted to be drawn tightly into place and securely locked by means of a threaded bolt 9, as shown. A packing-ring 8 is preferably interposed between the plate 5 and the seat 7 and wedge 8, respectively, which ring may be made of brass or other soft metal, or may consist of a simple gasket, or both gasket and ring may be used together. At the thick edge of the ring-shaped wedge S the chamber 6 is provided with a lateral opening normally closed by a hand-plate 10 and of such size that the plate 5 and wedge 8 may be placed in position or withdrawn through it. The open center of said wedge when in its locking position should coincide substantially with the bore of the pipe 2.

Above the plate 5 the pipe 2 is provided with an opening 11, leading to the sprinkling-pipe system 12, preferably through an intermediate chamber 13, containing an ordinary check-valve 14, which will normally exclude from the pipe 2 the compressed air containedin the sprinkling-pipe system,and thus provide between the supply system and the sprinkling-pipe system an intermediate chamber not subject to the pressures in either of said systems.

For the purpose of breaking the plate 5, and thus admitting water to the sprinkling-pipe system 12 I have shown a weight 16 normally suspended above the plate 5 at such a distance therefrom that when released it will acquire sufficient momentum in falling upon said plate to enable it to break the same. I prefer to use for this weight a piece of heavy pipe sharpened at its lower edge 17, and I also prefer to weaken the plate 5 by forming a circular groove 18 in one or both faces thereof, the diameter of said circle being equal to that of the edge 17 on the bottom of the weight 16 and said groove being located IOC directly beneath the same, so that the weight 16 when it falls will strike the weakened portions of the plate 5 and will make a clean cut through said plate, whence it will result that in the operation of the device the weight will pass completely through plate 5 and will fall to the bottom of the pipe 2, where it may be received on a spring-buffer 19. I prefer to make the weight 16 tubular rather than solid in order that if it fails to fracture completely the plate 5 or becomes wedged therein it may not obstruct the passage of the water, which will flow through the hollow center of said weight.

The weight 16 is normally suspended by suitable tripping mechanism, which may be contained within a chamber 20, bolted to the top of the pipe 2, and may consist of a pivoted lever 21, passing at one end under a link or bail 22, pivoted to the top of the weight 16 and normally maintained in a horizontal position by a spindle 23 bearing against its other end and held down upon the same by the pressure of the compressed air in the sprinkling-pipe system on the top of a valve 24, to which said spindle is attached or otherwise connected, which valve normally is closed tightly against a suitable seat 25. The valve 24 operates within a chamber 26, connected to the sprinkling-pipe system by a pipe 27, thereby rendering the compressedair pressure in said system operative upon said valve.

The operation of the mechanism above described may be summarized as follows: The lower part of the vertical pipe 2 being in free communication with the supply-pipe 4 is filled with water having the supply-prev sure, which is kept by the plate 5 from entering any part of the system above it. The sprinkling-pipe system with its connections, including the chambers 18 and 26 and the pipe 27, are normally filled with air under pressure, which, acting upon the valve 24, holds the lever 21 in its horizontal position, with the weight 16 suspended therefrom above the plate 5. The area of the valve 24 and the position of the fulcrum of the lever 21 are of course calculated with reference to the weight 11 and to the air-pressure which it is desired to maintain in the sprinkling-pipe system. The pipe 2 above the plate 5 and the chamber 20 are normally subject to atmospheric pressure only. Upon the occurrence of a fire or other event whereby the pressure of the compressed air is sufficiently reduced the weight 16 will overcome the resistance of the valve 24, tilt the lever 21, and slide off its end, immediately falling upon the plate 5 and breaking the same, as above described, thereby permitting the water to fiood the system through the chamber 13. To restore the device to its normal condition, the supply is shut off, thesprinkling-pipe system is drained through a pipe 28, leading from the chamber 13 and normally kept closed, and the chambers 15 and 20 and the pipe connections below them are drained through a small pipe 29.

The check-valve 14, if it has not already closed of its own accord, is closed by hand;access thereto being had through a hand-plate 30, forming one side of the chamber 13, and the sprinkling-pipe system is filled with compressed air under the desired pressure, thereby holding the valves 14 and 24 to their seats. Hand-plates 31 and 32, giving access, respectively, to the bottom of the pipe 2 and to the chamber 20, are next taken off, and the weight 16 is removed from the bottom of said pipe and restored to its normal position on the end of the horizontal lever 21. The hand-plate 10 is then removed, the wedge 8 and the rim of the broken plate 5 taken out, and a new plate 5 inserted in the chamber 6 and clamped in place by said wedge. The hand-plates 10, 31, and 32 are then bolted in place and water is turned on in the sup pl y-pipe 4, thus restoring the system to its normal condition.

The pipe 29, since it leads from the intermediate chamber 15, may be left open under normal conditions, and I prefer to connect it to a water rotary or similar device adapted to give an alarm upon the flooding of the system and also to an electric alarm, as is customary.

The pipe 27 should be connected with the sprinklingpipe system 12 at a considerable height above the plate 5 in order to prevent the water which sometimes drains from. the sprinkling-pipes and accumulates at the bottom thereof from flowing therefrom into the chamber 26 and water-columning the valve 24, whereby the proper operation of my device might be prevented.

It will be seen that my improvement is exceedingly simple of construction and that being dependent for its operation upon the breaking of a frangible part or member it cannot be injuriously affected by corrosion no matter howlong the system may stand without use. Furthermorathe apparatus cannot be affected by a water-hammer nor watercolumn, nor be caused to operate otherwise than by the action of the breaking device, the releasing mechanism of which may be made as sensitive as desired.

I do not consider my invention to be limited to any of the details of form or material of the frangible device herein described nor to the mechanism described for breaking the same, as my invention resides, broadly, in a frangible device through the instrumentality of which the water is directly or indirectly kept out of the system of sprinkling-pipes, in combination with means for automatically breaking said device upon the occurrence of certain predetermined conditions.

I claim as my invention 1. In a device of the character described, a frangible device located between the supply system and the sprinkling-pipe system and normally holding in check Water under pressure contained in said supply system, in combination with means for breaking said frangi ble device, said means being operative upon a reduction of pressure in the sprinklingpipe system.

2. In a device of the character described, the combination of a pipe having connections with the supply system and with the sprinkling-pipe system, a frangible device contained in said pipe and normally separating said systems,a check-valve located above said frangible device and providing a chamber under normal atmospheric pressure, and means contained in said chamber for breaking said frangible device, and arranged to operate upon a reduction of pressure in the sprinkling-pipe system.

3. In a device of the character described, the combination of a frangible device located between the supply system and the sprinkling-pipe system, a tubular weight normally suspended above said device, and means for automatically releasing said weight upon a reduction of pressure in the sprinkling-pipe system.

4. In a device of the character described, the combination of a vertical pipe having connections with the supply system and with the sprinkling-pipe system, a frangible plate contained in said pipe and normally separating said systems, a ring-shaped wedge whereby said plate is removably clamped in place, a weight normally suspended above said plate, and means for releasing said weight upon the reduction of pressure in the sprinkling-pipe system.

5. In a device of the character described, the combination of a frangible plate weakened on a circular line, a hollow pipe normally suspended above said plate and having substantially the same diameter as said circle, and means for automatically releasing said pipe.

6. In a device of the character described, the combination of a pipe provided with an inlet and an outlet, a frangible device through the instrumentality of which said pipe is kept closed between said inletail'd outlet, a valve upon which the air -pressure in the sprinkling pipe system is operative, and

a frangible device, valves 14 and 24: providing 4 an intermediate chamberbetween said device and the sprinkling-pipe system, pipe connec tions between the top of said valve 24 and the sprinkling-pipe system, and means controlled by said valve for automatically breaking said frangible device.

9. In a device of the character described, the combination with a frangible plate separating the supply system and the sprinklingpipe system, of a weight normally suspended above the same, and means for automatically releasing said weight, comprising a lever on one end of which said weight is suspended, a valve provided with a spindle bearing against the opposite end of said lever, and pipe connections between the top of said valve and the sprinkling-pipe system.

10. The combination of a vertical pipe 2 containing a frangible plate 5, a weight 16 normally suspended above the same, a cham ber 13 communicating with the sprinklingpipe system and containing a check-valve 14:, and suspending and releasing mechanism for said weight, comprising a lever 21, avalve 24 controlling the movement of the same, and pipe connections between the top of said valve 24: and the sprinkling-pipe system.

In testimony whereof I have hereunto subscribed my name this 2d day of December, 1899.

JOHN H. DERBY.

Witnesses:

ROSE M. RILEY, E. D. CHADWICK. 

